A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. A laser differs from other sources of light in that it emits light coherently. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Although there are different spatial modes for laser light, the most common is the TEM00 mode in which laser light is generated with a Gaussian intensity profile. A Gaussian intensity profile or Gaussian beam has transverse electric field and intensity (irradiance) distributions that are well approximated by Gaussian functions.